Liquid crystal display device with touch sensor, and electronic apparatus

ABSTRACT

A liquid crystal display device with a touch sensor has a liquid crystal display function and a touch sensor function is providing and includes a first substrate including a pixel electrode and a first electrode; a second substrate including a second electrode; and a liquid crystal layer provided between the first substrate and the second substrate. When the liquid crystal display function is activated, the first and second electrodes are supplied with common voltage. When the touch sensor function is activated, the first electrode is applied with a first signal, and the second electrode is configured to receive the first signal to be a second signal as a touch detecting signal.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.13/948,907 filed on Jul. 23, 2013, which claims priority to JapanesePriority Patent Application No. JP 2012-163421 filed in the Japan PatentOffice on Jul. 24, 2012, and JP 2013-151009 filed in the Japan PatentOffice on Jul. 19, 2013, the entire content of which is herebyincorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to technologies used in a liquid crystaldisplay device (LCD), a touch sensor (also referred to as a touch panel(TP)), a liquid crystal display device with a touch sensor (liquidcrystal touch panel module), an electronic apparatus, and the like.Specifically, the present disclosure relates to technologies used in aliquid crystal display device with an in-cell capacitive touch sensor.

2. Description of the Related Art

As a liquid crystal display device with a touch sensor having a liquidcrystal display function with a touch sensor function implemented, anin-cell touch panel configuration is employed especially for the purposeof reduction in thickness.

An example of the configuration of a related liquid crystal displaydevice with an in-cell capacitive touch sensor (for example, JapanesePatent Application Laid-open Publication No. 2009-244958(JP-A-2009-244958)) includes an array substrate, a color filter (CF)substrate, and a liquid crystal layer therebetween that are elementsconstituting the liquid crystal display panel. The configuration uses acommon electrode (referred to as COM) on the CF substrate as atransmitting electrode (referred to as Tx) that is an elementconstituting the touch sensor function, and a detection electrode on theCF substrate as a receiving electrode (referred to as Rx). That is, theliquid crystal display function and the touch sensor function share thesame electrode section and wiring.

In the above-described configuration example, a horizontal electricfield mode or a vertical electric field mode may be applied as a drivingsystem of the liquid crystal layer. The horizontal electric field modeis exemplified by fringe field switching (FFS) mode, in-plane switching(IPS) mode, etc. The vertical electric field mode is exemplified bytwisted nematic (TN) mode, vertical alignment (VA) mode, electricallycontrolled birefringence (ECB) mode, etc.

In the case of the horizontal electric field mode, the wiring of thecommon electrode COM serving as the transmitting electrode Tx is onlyprovided to a substrate (array substrate) on one side. On the otherhand, in the case of the vertical electric field mode, the wiring of thecommon electrode COM serving as the transmitting electrode Tx exists onboth top and bottom substrates, which are the array substrate and the CFsubstrate. That is, the configuration of the vertical electric fieldmode has one additional wiring layer of the common electrode comparedwith that of the horizontal electric field mode.

The liquid crystal display device with a touch sensor and the liketypically have problems and requirements such as slimming down, spacesaving, simplification and reduction of manufacturing process and parts,that is, cost reduction by the simplification, and improvement indisplay quality and touch detection accuracy. Specifically, with regardto the simplification and reduction, employing an in-cell configurationin which an electrode and wiring are shared by different functions asdescribed in the above configuration example enables reducing the numberof layers to thereby achieve cost reduction.

An example of the related art of the above-described in-cell liquidcrystal display device with a touch sensor is disclosed, for example, inPCT International Publication No. WO2007/070725. This patent document(“TOUCH SCREEN LIQUID CRYSTAL DISPLAY”) discloses “liquid-crystaldisplay (LCD) touch screens that integrate the touch sensing elementswith the display circuitry.”

With regard to the related liquid crystal display devices with anin-cell capacitive touch sensor, specifically with regard toconfiguration examples of sharing type in which the liquid crystaldisplay function and the touch sensor function shared the same electrodesection is shared (for example, as described in JP-A-2009-244958), atransparent electrode made of indium tin oxide (ITO) needs to bedeposited, for example, on the color filter of the CF substrate toprocess a sensor pattern (pattern of the receiving electrode) for thetouch sensor function in the manufacturing process of the liquid crystaldisplay device with a touch sensor.

However, the manufacturing process of the liquid crystal display devicewith a touch sensor of sharing type requires a step for processing thesensor pattern and the like, so that the process is more complicatedthan that of the related liquid crystal display device with a touchsensor of non-sharing type and the like.

For the foregoing reasons, there is a need for a liquid crystal displaydevice with an in-cell capacitive touch sensor (specifically, of sharingtype) with a simplified configuration.

SUMMARY

According to an aspect, a liquid crystal display device with a touchsensor has a liquid crystal display function and a touch sensorfunction. The liquid crystal device includes a first substrate includinga pixel electrode and a first electrode; a second substrate including asecond electrode; and a liquid crystal layer provided between the firstsubstrate and the second substrate. When the liquid crystal displayfunction is activated, the first and second electrodes are supplied withcommon voltage. When the touch sensor function is activated, the firstelectrode is applied with a first signal, and a second signal isdetected through the second electrode.

According to another aspect, an electronic apparatus includes the liquidcrystal display device with a touch sensor.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram illustrating the principle of a mutual capacitivetouch sensor;

FIG. 2 is a diagram illustrating the principle of the mutual capacitivetouch sensor;

FIG. 3 is a diagram illustrating the principle of the mutual capacitivetouch sensor;

FIG. 4 is a diagram illustrating a configuration example of a touchdetection region (touch detection unit U) in a touch panel;

FIG. 5 is a diagram illustrating a configuration of a pixel (cell) in aTFT-LCD;

FIG. 6 is a diagram illustrating a configuration of a pixel (cell) in aTFT-LCD;

FIG. 7 is a diagram illustrating a configuration example of a sharingtype liquid crystal display device in a horizontal electric field modeas a first comparative example;

FIG. 8 is a diagram illustrating a configuration example of a sharingtype liquid crystal display device in a vertical electric field mode asa second comparative example;

FIG. 9 is a cross-sectional view illustrating a schematic configurationof a main part of a panel section of a liquid crystal display devicewith a touch sensor in a first embodiment of the present disclosure;

FIG. 10 is a cross-sectional view illustrating the schematicconfiguration of a main part of a panel section of a liquid crystaldisplay device with a touch sensor in a second embodiment of the presentdisclosure;

FIG. 11 is a diagram illustrating the planar configuration of wiringpattern and the like of the liquid crystal display device with a touchsensor in the second embodiment;

FIG. 12 is a diagram illustrating an enlarged configuration of FIG. 11;

FIG. 13 is a diagram illustrating a first modification of the secondembodiment;

FIG. 14 is a diagram illustrating a second modification of the secondembodiment;

FIG. 15 is a diagram illustrating a third modification of the secondembodiment;

FIG. 16 is a diagram illustrating a fourth modification of the secondembodiment;

FIG. 17 is a diagram illustrating a functional block configuration of aliquid crystal touch panel module and an electronic apparatus of a thirdembodiment;

FIG. 18 is a timing chart of driving waveforms of the liquid crystaltouch panel module of the third embodiment;

FIG. 19 is a diagram illustrating a configuration example of a driver ofthe liquid crystal touch panel module of the third embodiment;

FIG. 20 is a diagram illustrating a first modification of theconfiguration example of the driver of the liquid crystal touch panelmodule of the third embodiment;

FIG. 21 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the presentembodiment is applied;

FIG. 22 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied;

FIG. 23 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied;

FIG. 24 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied;

FIG. 25 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied;

FIG. 26 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied;

FIG. 27 is a diagram illustrating an example of the electronic apparatusto which the liquid crystal display device according to the embodimentis applied; and

FIG. 28 is a diagram illustrating an example of an electronic apparatusto which the liquid crystal display device according to the embodimentis applied.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described indetail with reference to drawings. The same reference numerals areassigned to the same portions in principle throughout all the drawingsfor explaining the embodiments, and redundant explanation thereof willnot be repeated. For the purpose of explanation, it is assumed that atouch panel display plane is along the X-Y direction, a directionorthogonal thereto (direction of the line of sight) is the Z direction,a direction in which a gate line extends is the X direction, and adirection in which a source line extends is the Y direction. In additionto the reference numerals, omission marks such as G, S, Tx, and Rx areused as appropriate. In cross-sectional views, hatching may be partiallyomitted for the sake of clarification.

The present embodiment provides an electronic apparatus to which theliquid crystal display device with an in-cell capacitive touch sensor,which enables simplification of a sharing type panel (especially, anelectrode layer) configuration in a vertical electric field mode, and anelectronic apparatus therewith.

1. Liquid Crystal Display Device with Touch Sensor

Before describing about the present embodiment in detail, technologiesabout the liquid crystal display device with a touch sensor will besequentially described hereinafter for the sake of clarity.

1-1. Principle of Touch Panel (1)

FIG. 1, FIG. 2, and FIG. 3 are diagrams illustrating the basic principleof a mutual capacitive touch sensor (touch panel). The presentembodiment also complies with the principle. FIG. 1 is a diagramillustrating a basic structure of a touch sensor (touch panel) T. FIG. 2is a diagram illustrating an equivalent circuit of FIG. 1. FIG. 3 is adiagram illustrating a signal voltage at the time of touch detection inFIG. 1 and FIG. 2. The touch sensor may be referred to as aninput/output device in some cases in this specification.

The touch panel T illustrated in FIG. 1 has a configuration including atouch drive electrode E1 (transmitting electrode Tx) and a touchdetection electrode E2 (receiving electrode Rx) that are arrangedopposed to each other with a dielectric D interposed therebetween, bywhich a capacitor (in other words, a capacitative element) C1 is formed.The capacitor C1 is an electrostatic capacitor for touch detection. Thepresence or absence of touching is detected from a change in thecapacitor C1 due to the proximity of an electric conductor M, such as afinger, to the surface on the touch detection electrode E2 side. Asillustrated in FIG. 2, one end of the capacitor C1 is connected to analternating current signal source AS via a resistor R_(Tx), and isconnected to a voltage detector DET via a resistor R_(Rx), and the otherend is grounded. To turn on the touch sensor function, the voltage of afirst signal s1 that is a touch driving signal in an alternating currentsquare wave is applied to the touch drive electrode E1 from thealternating current signal source AS. Then, electrical current flows viathe capacitor C1, and the voltage of a second signal s2 that is a touchdetection signal is detected (output) at the voltage detector DET. Theinput first signal s1 illustrated in FIG. 3 is voltage in an alternatingcurrent square wave having a predetermined frequency. The output secondsignal s2 (detecting voltage Vdet) is voltage V1 in the absence oftouching, and changes to voltage V2 in the presence of touching.

In a state where the electric conductor M, such as a finger, is notclose to the touch detection electrode E2 on the front side of the touchpanel T (in the absence of touching), electrical current I1corresponding to the capacitance value of the capacitor C1 flowsaccording to the charge and discharge of the capacitor C1 in response tothe input of the first signal s1. At this time, the shape of potential(detecting voltage Vdet) of the touch detection electrode E2 at theother end of the capacitor C1 detected by the voltage detector DET isthe voltage V1 of the second signal s2. During the absence of touching,the voltage V1 is maintained substantially constant.

In a state where the electric conductor M is close to the touchdetection electrode E2 on the front side of the touch panel T (in thepresence of touching), the capacitor C2 formed by the electric conductorM is added to the capacitor C1 in series. In this state, the electricalcurrent I1 and electrical current 12 corresponding to the capacitancevalues of the capacitor C1 and the capacitor C2 flow according to thecharge and discharge of the capacitor C1 and the capacitor C2,respectively. At this time, the shape of potential (detecting voltageVdet) of the touch detection electrode E2 at the other end of thecapacitor C1 detected by the voltage detector DET is the voltage V2 ofthe second signal s2 due to decrease in electric field by the electricconductor M. The electric potential of the touch detection electrode E2is the electric potential of a divided voltage determined by theelectrical current values of the electrical current I1 and theelectrical current I2 flowing via the capacitor C1 and the capacitor C2,respectively. Accordingly, the voltage V2 of the second signal s2 in thepresence of touching is lower than the voltage V1 in the absence oftouching. In the voltage detector DET or a corresponding touch detectioncircuit, the detecting voltage Vdet (the voltage V1 or the voltage V2)of the second signal s2 is compared with a predetermined thresholdvoltage Vth. If the detecting voltage Vdet is smaller than the thresholdvoltage Vth as with the voltage V2 in FIG. 3, for example, the presenceof touching is detected. Alternatively, the detection may be performedby comparing the amount of change from the voltage V1 to the voltage V2against a predetermined threshold voltage Vth.

1-2. Principle of Touch Panel (2)

FIG. 4 is a diagram illustrating a configuration example of a touchdetection region (touch detection unit U) in the touch panel Tillustrated in FIG. 5. In a plane constituting a touch detection regionof the panel (herein referred to as the X-Y direction), provided are awiring pattern of the touch drive electrode E1 (transmitting electrodeTx) and a wiring pattern of the touch detection electrode E2 (receivingelectrode Rx), and the touch detection unit U is constituted of acapacitor formed at each intersecting part thereof. For example, thetouch drive electrode E1 (transmitting electrode Tx) is formed in aplurality of lines parallel to the X direction of the plane of a firstsubstrate, and the touch detection electrode E2 (receiving electrode Rx)is formed in a plurality of lines parallel to the Y direction of theplane of a second substrate. The lines of the touch drive electrode E1and the touch detection electrode E2 may have a configuration withblocks each corresponding to a plurality of pixel lines of a liquidcrystal display device, for example. In FIG. 4, for example, a pluralityof pixel lines correspond to one block. For example, in response tosequential application (scanning) of the first signal s1 to a group ofE1 blocks from a driver, the touch detection unit U corresponding to oneor more touch positions in the touch detection region may be detected bycalculation processing based on the second signal s2 detected (output)from a group of E2 blocks.

The configuration is not limited to the example described above. Forexample, the touch drive electrode E1 (transmitting electrode Tx) may beformed as a solid layer on the surface of the first substrate, and thetouch detection electrode E2 (receiving electrode Rx) may be formed in amatrix in a unit of divided region in the X direction and the Ydirection on the surface of the second substrate. The resolution oftouch detection depends on the design of the pattern. In thisspecification, “solid layer” denotes a layer that is not processed intoa predetermined shape after deposition.

1-3. Configuration of TFT-LCD Pixel

FIG. 5 is a diagram illustrating the configuration of a pixel (cell) ina TFT-LCD. FIG. 6 is a diagram illustrating an equivalent circuitcorresponding to the configuration in FIG. 5. As illustrated in FIG. 5,the pixels (cells) are configured in a matrix by intersecting of gatelines 41 (gate lines G) parallel to the horizontal (X) direction andsource lines 42 (source lines S) parallel to the vertical (Y) direction.Each of the gate lines 41 (gate lines G) is connected to a gateelectrode of a TFT 44, and each of the source lines 42 (source lines S)is connected to a source electrode of the TFT 44. One of the terminalsof a pixel capacitor 43 is connected to a drain electrode of the TFT 44.Each pixel has a holding capacitor 45 connected to a holding capacitorline 46 (or a common electrode) parallel to the X direction. FIG. 6illustrates an equivalent circuit corresponding to the configuration ofFIG. 5. One of the terminals of the pixel capacitor 43 and one of theterminals of the holding capacitor 45 are connected to the drainelectrode of the TFT 44. The other terminal of the pixel capacitor 43and the other terminal of the holding capacitor 45 are connected as theholding capacitor line 46, and common voltage is supplied thereto.

1-4. Liquid Crystal Display Device with Touch Sensor (Non-Sharing Type)

The touch panel T may have an in-cell type configuration provided in theliquid crystal display panel (in-cell liquid crystal display device witha touch sensor). When the vertical electric field mode is applied as thedrive system of the liquid crystal layer, the first substrate (arraysubstrate) has a first common electrode section COM1 and the secondsubstrate (CF substrate) has a second common electrode section COM2.When the horizontal electric field mode is applied, the first substrate(array substrate) has the common electrode COM.

1-5. In-cell Liquid Crystal Display Device with Touch Sensor (SharingType)

The in-cell liquid crystal display device with a touch sensor may have asimplified configuration (sharing type) in which a common electrodesection originally included in the liquid crystal display device is alsoused as part of electrodes constituting the touch sensor (specifically,the touch drive electrode E1) (for example, see JP-A-2009-244958). Acommon driving signal (common voltage) applied to the common electrodesection for liquid crystal display is also used as a signal for touchsensor. As for the drive system, signals for respective functions areapplied to the same electrode section in a time division manner (FIG. 18to be described later).

In the case of the sharing type and the vertical electric field mode(TN, VA, ECB, and the like), the second common electrode section COM2 onthe second substrate (CF substrate) is also used (shared) as thetransmitting electrode Tx. In the vertical electric field mode, anelectric field VE is generated in the liquid crystal layer in thevertical direction (Z direction) through the common driving signal(common voltage) to the upper and lower common electrode sections (thecommon electrode COM1 and the common electrode COM2) and a pixel signalto the terminals of the pixel capacitor, so that the state of each pixelis controlled (modulated).

In the case of the sharing type and the horizontal electric field mode(FFS, IPS, and the like), the common electrode COM on the firstsubstrate (array substrate) is also used (shared) as the transmittingelectrode Tx of the touch sensor function, and the receiving electrodeRx is provided on the second substrate (CF substrate). In the horizontalelectric field mode, an electric field in the horizontal direction (X-Ydirection) is generated in the liquid crystal layer through the commondriving signal (common voltage) to the common electrode COM and thepixel signal to the terminals of the pixel capacitor, so that the stateof each pixel is controlled (modulated).

1-6. First Comparative Example Sharing Type—Horizontal Electric FieldMode

FIG. 7 illustrates the schematic configuration of a main part in thecase of the sharing type and the horizontal electric field mode (firstcomparative example). A panel section 910 of the liquid crystal displaydevice with a touch sensor includes the common electrode COM (includinga terminal of the holding capacitor 45 and a terminal of the holdingcapacitor line 46), which is also used (shared) as the transmittingelectrode Tx, as the first electrode 911. The panel section 910 includesa pattern of the receiving electrode Rx as the second electrode 912(receiving electrode Rx) on the front side of a CF substrate 20. Thearray substrate 10 includes a glass substrate 11 on which the gate lines41 (gate lines G), the source lines 42 (source lines S), the pixelcapacitors 43, the TFTs 44, the first electrode 911 serving as thetransmitting electrode Tx and the common electrode COM, an insulatinglayer, and the like are formed. The CF substrate 20 includes a glasssubstrate 21 having an inner surface (a side adjacent to a liquidcrystal layer 30) on which a color filter 22, the insulating layer, andthe like are formed. The second electrode 912 (receiving electrode Rx)is formed on the front side (line of sight side) of the CF substrate 20.The first electrode 911 (transmitting electrode Tx) and the secondelectrode 912 (receiving electrode Rx) constitute the capacitor C fortouch sensor.

1-7. Second Comparative Example Sharing Type—Vertical Electric FieldMode

FIG. 8 illustrates the schematic configuration of a main part in thecase of the sharing type and the vertical electric field mode (secondcomparative example). In a panel section 920 of the liquid crystaldisplay device with a touch sensor, the first common electrode sectionCOM1 provided on the array substrate 10 is electrically connected to thesecond common electrode section COM2 provided on the CF substrate 20 viaa vertical conducting part 61 (including a conductive particle 62). Thefirst common electrode section COM1 and the second common electrodesection COM2, which are also used (shared) as the transmitting electrodeTx (the transmitting electrode Tx1 and the transmitting electrode Tx2),are provided as the first electrode 921 and the second electrode 922,respectively. The pattern of the receiving electrode Rx as a thirdelectrode 923 is provided on the front side of the CF substrate 20. Thearray substrate 10 includes the glass substrate 11 on which the gatelines 41 (gate lines G), the source lines 42 (source lines S), the pixelcapacitors 43, the TFTs 44, the first electrode 921 serving as thetransmitting electrode Tx1 and the common electrode COM1, an insulatinglayer, and the like are formed. The CF substrate 20 includes the glasssubstrate 21 having an inner side (a side adjacent to the liquid crystallayer 30) on which the color filter 22, the insulating layer, the secondelectrode 922 serving as the transmitting electrode Tx2 and the commonelectrode COM2, and the like are formed. The third electrode 923(receiving electrode Rx) is formed on the front side (line of sightside) of the CF substrate 20. The second electrode 922 (transmittingelectrode Tx2) and the third electrode 923 (receiving electrode Rx)constitute the capacitor C for touch sensor.

2. First Embodiment

On the basis of the above description, a first embodiment will bedescribed with reference to FIG. 9 and the like. In the configuration ofthe first embodiment, in contrast to the second comparative example(FIG. 8), the first common electrode section COM1 on the array substrate10 is used as the transmitting electrode Tx, the second common electrodesection COM2 at the inner side on the CF substrate 20 is used as thereceiving electrode Rx, and the pattern layer of the receiving electrodeRx on the front surface of the CF substrate 20 is eliminated.

In the case of the panel section 920 of the liquid crystal displaydevice with a touch sensor in the second comparative example (of thevertical electric field mode and the sharing type), with regard to theliquid crystal display function, wiring layers of the common electrodeCOM (the common electrode COM1 and the common electrode COM2) areprovided to both the array substrate 10 and the CF substrate 20, whichare the upper and lower substrates. That is, a first common electrodewiring layer (common electrode COM1) is provided on the array substrate10 and a second common electrode wiring layer (common electrode COM2) isprovided at the inner side on the CF substrate 20. Those wiring layersare electrically connected through a frame part (non-display area) orthe like on the outer side of a display area. With reference to FIG. 8,the first electrode 921 serving as the transmitting electrode Tx1 andthe common electrode COM1 and the second electrode 922 serving as thetransmitting electrode Tx2 and the common electrode COM2 are connectedthrough the vertical conducting part 61. Further, in the secondcomparative example, the pattern of the receiving electrode Rx, which ismade of ITO or the like, is provided on the outer side (front side) ofthe CF substrate 20.

On the basis of the characteristics of the comparative examples, in thefirst embodiment (FIG. 9), a panel section 1 of the liquid crystaldisplay device with a touch sensor of the vertical electric field modeand the sharing type has a simplified configuration by sharing anelectrode and a wiring layer of each function of the liquid crystaldisplay and the touch sensor, as described below. That is, the firstcommon electrode wiring layer (the common electrode COM1 and thetransmitting electrode Tx1) on the array substrate 10 is used as amonolayer touch drive electrode (transmitting electrode Tx), the secondcommon electrode wiring layer (the common electrode COM2) on the CFsubstrate 20 is newly also used as the touch detection electrode(receiving electrode Rx), and an Rx pattern on the front surface of theCF substrate 20 is eliminated. That is, the panel section 1 of theliquid crystal display device with a touch sensor in the firstembodiment has a configuration in which a panel or a substrate structureis simplified so that the number of electrode layers is lower than thatin the comparative example (FIG. 8) by one. Accordingly, cost reductionand the like are achieved by the simplification of the manufacturingprocess and steps of the panel.

2-1. Liquid Crystal Display Device with Touch Sensor (1)

FIG. 9 illustrates the (Y-Z cross sectional) schematic configuration ofa main part of the panel section 1 of the liquid crystal display devicewith a touch sensor in the first embodiment. The panel section 1 of theliquid crystal display device with a touch sensor includes the arraysubstrate 10 and the CF substrate 20 opposed to each other, and theliquid crystal layer 30 therebetween. The liquid crystal layer 30 isdriven in the vertical electric field mode. As the sharing type, a firstelectrode 51 serving as the transmitting electrode Tx and the commonelectrode COM1 is provided on the array substrate 10, and a secondelectrode 52 serving as the receiving electrode Rx and the commonelectrode COM2 is provided on the inner surface (a side adjacent to theliquid crystal layer 30) on the CF substrate 20. The capacitor C fortouch sensor is formed between the first electrode 51 serving as thetransmitting electrode Tx and the second electrode 52 serving as thereceiving electrode Rx.

The first electrode 51 functions as both the first common electrodewiring layer (common electrode COM1) of the liquid crystal displayfunction and the touch drive electrode (transmitting electrode Tx) ofthe touch sensor function. In the first electrode 51, a pattern of thetransmitting electrode Tx for touch driving is formed using atransparent electrode made of ITO. The common electrode COM1 includes aterminal of the holding capacitor 45 provided for each pixel, theholding capacitor line 46 thereof, and the like. That is, the firstelectrode 51 serving as the common electrode COM1 forms the holdingcapacitor.

The second electrode 52 functions as both the second common electrodewiring layer (common electrode COM2) of the liquid crystal displayfunction and the touch detection electrode (receiving electrode Rx) ofthe touch sensor function. In the second electrode 52, a pattern of thereceiving electrode Rx for touch detection is formed using thetransparent electrode made of ITO.

The array substrate 10 includes the glass substrate 11 on which the gatelines 41 (gate lines G), the source lines 42 (source lines S), the pixelcapacitors 43, the TFTs 44, the holding capacitors 45, the holdingcapacitor lines 46, the first electrode 51 serving as the transmittingelectrode Tx and the common electrode COM1, the insulating layer, andthe like are formed. The first electrode 51 includes a terminal of theholding capacitor 45 and the holding capacitor line 46. The gate lines41 (gate lines G) are arranged in such a manner that a plurality oflines extend in parallel to the X direction with a wiring pattern ofmetal and the like. The source lines 42 (source lines S) are arranged insuch a manner that a plurality of lines extend in parallel to the Ydirection with a wiring pattern of metal and the like. The pixelcapacitor 43 has a pattern of the transparent electrode made of ITO orthe like as a terminal, and respective pixel capacitor parts are formedcorresponding to a plurality of pixels formed in a matrix in the displayarea. The pixel capacitor 43 is formed on the insulating layer and has aconfiguration in which the liquid crystal layer 30 is arranged thereonvia an alignment film. The terminal of the pixel capacitor 43 is alsoreferred to as a pixel electrode.

The CF substrate 20 includes the glass substrate 21 having an innersurface (a side adjacent to the liquid crystal layer 30) on which thecolor filter 22, the insulating layer, the second electrode 52 servingas the receiving electrode Rx and the common electrode COM2, and thelike are formed. For example, the color filter 22 has a pattern ofperiodic arrangement of each color of red (R), green (G), and blue (B).Either one of the colors R, G, and B is associated to each one pixel(subpixel).

The liquid crystal layer 30 is a layer in which the orientation of theliquid crystal is controlled according to an electric field state due toapplied voltage so as to modulate transmitted light. The liquid crystallayer 30 adopts the vertical electric field mode, and the state of eachpixel is modulated according to an electric field state generated byvoltage applied by the upper and lower electrodes of the liquid crystallayer 30 (a common driving signal (common voltage Vcom) and a pixelsignal of the pixel capacitor 43). The upper and lower substrates (thearray substrate 10 and the CF substrate 20) are physically connected,for example, by a sealing part 60 at the frame part or the like of theouter side of the display area, and thereby the liquid crystal layer 30is sealed.

Unlike the comparative examples (for example, FIG. 8), the firstelectrode 51 and the second electrode 52 are not electrically connectedvia the vertical conducting part 61 and the like, and are independentlydriven by drivers (FIG. 17 to be described later) each connected to thefirst electrode 51 or the second electrode 52.

FIG. 9 does not illustrate a polarizing plate (provided below the arraysubstrate 10 and/or above the CF substrate 20), the orientation film(provided between the upper and lower substrates and the liquid crystallayer 30), and the like that are general elements included in the panelsection 1 of the liquid crystal device with a touch sensor. The panelsection 1 may include other additional elements (an antistatic layer, aprotective film, and the like), which are not illustrated.

3. Second Embodiment

A second embodiment will be described with reference to FIG. 12 to FIG.14, for example. In the first embodiment, a distance between the firstelectrode 51 serving as the transmitting electrode Tx and the secondelectrode 52 serving as the receiving electrode Rx is relatively shortso that the capacitance formed therebetween may increase. Such anincrease of the capacitance may have some effect on the sensibility ofthe touch detection. Accordingly, in the second embodiment, the patterndesigns are devised as follows for the first electrode 51 and the secondelectrode 52.

3-1. Liquid Crystal Display Device with Touch Sensor (2)

FIG. 10 illustrates the schematic configuration of a main part of thepanel section 1 of the liquid crystal display device with a touch sensorin the second embodiment. FIG. 10( a) is a diagram illustrating the X-Zcross section, and FIG. 10( b) is a diagram illustrating the Y-Z crosssection. On the array substrate 10, provided are the gate lines G, thesource lines S, the pixel capacitors 43, and a wiring layer of the firstelectrode 51 serving as the transmitting electrode Tx and the commonelectrode COM1 and including a terminal of the holding capacitance 45and the holding capacitance lines 46. FIG. 10 schematically illustratesthe positions and overlaps of respective components. For example, thegate lines G and the first electrode 51 serving as the transmittingelectrode Tx and the common electrode COM1 illustrated in FIG. 10 areformed in the same layer in the Z direction (similarly to FIG. 9).Although they are illustrated to overlap each other in FIG. 10, they areactually formed in separate regions in the same layer (FIG. 11). Thepositions of the layer of the first electrode 51 and the layer of thesecond electrode 52 may be vertically shifted in the Z direction. Forexample, the second electrode 52 (receiving electrode Rx) is positionedat the inner side of the CF substrate 20, more specifically, at thesurface adjacent to the liquid crystal layer 30 on the glass substrate21. However, the second electrode 52 may be positioned at an upperposition.

FIG. 11 is an X-Y plane diagram illustrating a pattern configurationexample of the first electrode 51 (transmitting electrode Tx), thesecond electrode 52 (receiving electrode Rx), or the like of the panelsection 1 of the liquid crystal display device with a touch sensor inthe second embodiment. The first electrode 51 serving as thetransmitting electrode Tx and the common electrode COM1 is formed as apattern parallel to the X direction. The first electrode 51 includes aterminal of the holding capacitor 45 and the holding capacitor line 46.

As illustrated in FIG. 10 and FIG. 11, in the second embodiment, apredetermined pattern different from that in the comparative example(FIG. 8) is formed for the second electrode 52 serving as the receivingelectrode Rx and the common electrode COM2 at the inner side of the CFsubstrate 20. The pattern of the second electrode 52 is separately usedas a first pattern part Rx1 and a second pattern part Rx2. The firstpattern part Rx1 is the sensor pattern Rx1 used for the touch detection.The second pattern part Rx2 is the floating pattern Rx2 used for loadreduction, and it is not used for the touch detection.

The sensor pattern Rx1 is arranged to overlap the source line 42 (sourceline S) parallel to the Y direction of the array substrate 10 in the X-Yplane view. That is, the sensor pattern Rx1 is also formed as astripe-shaped pattern parallel to the Y direction. The first electrode51 (transmitting electrode Tx) and the sensor pattern Rx1 form thecapacitor C for the touch sensor function. In this example, because eachpixel line (source line S) has a line of the sensor pattern Rx1, theresolution of the touch detection of the touch sensor function and theresolution of the pixel have one-to-one correspondence. The embodimentis not limited to this example, and the arrangement of lines of thesensor pattern Rx1 may be designed according to a required resolution ofthe touch detection. For example, one sensor pattern Rx1 may be arrangedper a plurality of source lines S.

The floating patterns Rx2 are arranged between the sensor patterns Rx1in the X-Y plane view, and do not overlap the source line 42 (sourceline S). The floating pattern Rx2 is also formed as a stripe-shapedpattern parallel to the Y direction. As illustrated in FIG. 11, aplurality of lines of the floating pattern Rx2 are arranged in afloating manner (independently) between two lines of the sensor patternRx1 corresponding to one pixel line. In FIG. 11, four lines of thefloating pattern Rx2 are arranged between two lines of the sensorpattern Rx1 as an example.

With the pattern and the arrangement structure, parasitic capacitance isreduced at the sensor pattern Rx1 of the receiving electrode Rx servingas the common electrode COM2 on the CF substrate 20 and at a portioncorresponding to an terminal of the holding capacitor 45 and the holdingcapacitor line 46 of the first electrode 51 serving as the transmittingelectrode Tx and the common electrode COM1 on the array substrate 10.The orientation of the liquid crystal layer 30 in the vertical electricfield mode is improved as well.

An end of the line of the sensor pattern Rx1 is fixedly connected to adriver (second electrode driver 202 in FIG. 17 to be described later).On the other hand, the line of the floating pattern Rx2 has basically afloating structure in the panel section 1. That is, the floating patternRx2 is separated from the outer side by a selection circuit (Rx2selection circuit 222 in FIG. 19) to be described later. The use of thefloating pattern Rx2 is switched between the liquid crystal displayfunction and the touch sensor function, so that an end of the line ofthe floating pattern Rx2 is connected to the selection circuit for itsdriving. When the switch of the selection circuit is turned off, theline of the floating pattern Rx2 is in a floating state (disconnected).

As illustrated in FIG. 11, in accordance with to the configuration ofthe Rx pattern, each wiring pattern of the first electrode 51, servingas the transmitting electrode Tx and the common electrode COM1 parallelto the X direction on the array substrate 10, is configured not to havea constant width but to have a smaller width (length in the Y direction)at a portion at which it overlaps the source line S and the sensorpattern Rx1 in the Y direction in the X-Y plane view. Thus, the area ofan overlapped portion 300 or the like is reduced. Accordingly, theparasitic capacitance (between the sensor pattern Rx1 and thetransmitting electrode Tx) is further reduced.

As illustrated in FIG. 11, in a manner corresponding to the separatedstructure of the receiving electrode Rx pattern, a slit 310 and the likeare provided between the line of the sensor pattern Rx1 and the line ofthe floating pattern Rx2, and between the lines of the floating patternRx2. With the slit 310 of the receiving electrode Rx pattern provided, afringe electric field is generated between the first electrode 51serving as the transmitting electrode Tx and the common electrode COM1on the array substrate 10, and the second electrode 52 serving as thereceiving electrode Rx and the common electrode COM2 on the CF substrate20. Accordingly, performance of the liquid crystal display function andthe touch sensor function is secured.

FIG. 12 illustrates a partially enlarged view of FIG. 11. In thisconfiguration example, the lines of the sensor pattern Rx1 and thefloating pattern Rx2 are arranged at predetermined pitches p1. The widthof the sensor pattern Rx1 and the width of the floating pattern Rx2 arethe same width r1.

As the slits, a slit SLa between the lines of the sensor pattern Rx1 andthe floating pattern Rx2 and a slit SLb between the lines of Rx2 areillustrated. The width of the slit SLa is a width L1, and the width ofthe slit SLb is the width L2. In this example, both widths of the slitsare the same width. The width of the transmitting electrode Tx isbasically a width h1, and may be a narrowed to width h2 at theoverlapped portion 300 and the like. That is, the width h2 of theoverlapped portion 300 is smaller than the basic width h1 of thetransmitting electrode Tx. In other words, the width h2 at theoverlapped portion 300 is smaller than the width h1 at a region otherthan the overlapped portion 300 of the transmitting electrode Tx.Specifically, in this example, the width of the receiving electrode Rxis the width h2 across the width r1 of the sensor pattern Rx1 at theportion where the transmitting electrode Tx and the sensor pattern Rx1overlap each other.

The embodiment is not limited to the above-described patternconfiguration example, and may be designed such that the numbers, shape,size, and the like of electrodes and/or slits vary according to aspecific implementation (a desired characteristic). For example, theembodiment has modifications as follows.

3-2. Modifications

FIG. 13, FIG. 14, FIG. 15, and FIG. 16 are diagrams illustratingmodifications of the configuration in FIG. 12. FIG. 13 is a diagramillustrating a first modification of the second embodiment. FIG. 14 is adiagram illustrating a second modification of the second embodiment.FIG. 15 is a diagram illustrating a third modification of the secondembodiment. FIG. 16 is a diagram illustrating a fourth modification ofthe second embodiment.

In the first modification of the second embodiment illustrated in FIG.13, the shape of the first electrode 51 serving as the transmittingelectrode Tx and the common electrode COM1 is changed, so that the widthof the first electrode 51 is changed at the upper part (closer to thegate line 41), not at the center of the holding capacitor line 46, onthe portion overlapping the sensor pattern Rx1. Similarly, the width ofthe transmitting electrode Tx may be changed to the width h2, which is anarrowed width, at the lower part. At the portion where the transmittingelectrode Tx and the sensor pattern Rx1 overlap, the length in the Xdirection of a portion with the width h2, which is a narrowed width ofthe transmitting electrode Tx, is longer than the width r1 of the sensorpattern Rx1 and is the same as the length xa between the floatingpatterns Rx2 adjacent to the sensor pattern Rx1 (xa>r1).

In the second modification of the second embodiment illustrated in FIG.14, the shape of the first electrode 51 serving as the transmittingelectrode Tx and the common electrode COM1 is changed, so that the widthh2, which is a narrowed width of the transmitting electrode Tx, is madelarger and the length in the X direction of a portion with the width h2,which is the narrowed width of the transmitting electrode Tx, is madesmaller than the width r1 of the sensor pattern Rx1 and is the same withthe width xb of the source line S (xb<r1) at the portion where thetransmitting electrode Tx and the sensor pattern Rx1 overlap.

In the third modification of the second embodiment illustrated in FIG.15, the first electrode 51 serving as the transmitting electrode Tx andthe common electrode COM1 has a constant width of the width h1. Thewidth r2 of the floating pattern Rx2 is smaller than the width r1 of thesensor pattern Rx1 (r1>r2). The width L2 of a slit SLb between thefloating patterns Rx2 is larger than the width L1 of a slit SLa betweenthe sensor pattern Rx1 and the floating pattern Rx2 (L1<L2). Theconfiguration opposite from the above may be employed (r1<r2, L1>L2).

In the fourth modification of the second embodiment illustrated in FIG.16, the shape of the transmitting electrode Tx is similar to the above(FIG. 12). The width r1 of the sensor pattern Rx1 is made larger and thecenter line of the sensor pattern Rx1 is shifted to the right relativeto the center line of the source line S, for example. That is, in theX-Y plane view, the sensor pattern Rx1 partially overlaps the sourceline S and projects to the right relative to the source line S, so thatit further overlaps the transmitting electrode Tx as much as theprojection. To reduce the capacitance due to the overlapping of thesensor pattern Rx1 and the transmitting electrode Tx, the width of theTx at the overlapped portion may be narrowed.

4. Third Embodiment

Next, a third embodiment will be described with reference to FIG. 17 toFIG. 19. The third embodiment describes a configuration example of aliquid crystal touch panel module 100 including the panel section 1 ofthe liquid crystal display device with a touch sensor and a driver ICthereof or the like, and a configuration example of an electronicapparatus 500 including the liquid crystal touch panel module 100.Specifically, a drive system with respect to the floating pattern Rx2 inthe second embodiment will be described as well.

4-1. Liquid Crystal Touch Panel Module, and Electronic Apparatus

FIG. 17 illustrates a functional block configuration example of theelectronic apparatus 500 including the liquid crystal touch panel module100 (liquid crystal display device with an in-cell capacitive touchsensor) in the third embodiment. Examples of the electronic apparatus500 may include various devices having the liquid crystal displayfunction and the touch sensor function such as a mobile terminal, a TVset, and a digital camera. The electronic apparatus 500 includes theliquid crystal touch panel module 100 and a control unit 501 forconnecting the same.

The liquid crystal touch panel module 100 includes the panel section 1of the liquid crystal display device with a touch sensor, and a touchsensor driver 101 (a first controller) and a liquid crystal displaydriver 102 (a second controller) both connected to the panel section 1.The liquid crystal touch panel module 100 and the control unit 501 areconnected via an interface (I/F) 502 of the touch sensor driver 101. Theinterface 502 includes the interface of a power supply and the interfaceof a touch sensor. The liquid crystal display driver 102 and the controlunit 501 are connected. The touch sensor driver 101 and the liquidcrystal display driver 102 are synchronized. In this configurationexample, although the touch sensor driver 101 (first controller) is amain control unit (superior to the liquid crystal display driver 102) ofthe liquid crystal touch panel module 100 (the panel section 1 of theliquid crystal display device with a touch sensor), the relationshipbetween the drivers may be reversed or the drivers may be integrated.For example, each of the touch sensor driver 101 and the liquid crystaldisplay driver 102 is implemented as an IC on an FPC substrate connectedto the panel section 1. For example, each driver is implemented using achip on film (COF) method and the like.

The panel section 1 of the liquid crystal display device with a touchsensor is configured as described above (for example, FIG. 9), andincludes a display area 71 including a pixel and a touch detectionregion (unit U), a frame part (not illustrated) on the outer sidethereof, and drivers each connected to electrodes or wirings (the gatelines G, the source lines S, the transmitting electrodes Tx, and thereceiving electrodes Rx) and the like in the display area 71. Examplesof the drivers include a gate driver 301, a source driver 302, a firstelectrode driver 201 serving as the transmitting electrode Tx and thecommon electrode COM1, and a second electrode driver 202 serving as thereceiving electrode Rx and the common electrode COM2. Each of thedrivers is implemented, for example, on the frame part on the outer sideof the display area 71, the lower glass substrate 11 or the upper glasssubstrate 21. Each driver is implemented using, for example, a chip onglass (COG) method, a low-temperature poly (polycrystalline) silicon(LTPS) method, and the like.

The drivers may be separated or integrated as appropriate. For example,the gate driver 301 and the first electrode driver 201 may beintegrated, or the source driver 302 and the second electrode driver 202may be integrated. The first electrode driver 201 or the secondelectrode driver 202 may be integrated with the touch sensor driver 101,and the gate driver 301 or the source driver 302 may be integrated withthe liquid crystal display driver 102.

The touch sensor driver 101 receives a video signal and the like fromthe control unit 501 of the electronic apparatus 500, and performstiming control for the liquid crystal display driver 102 and touchdetection control for the panel section 1 of the liquid crystal displaydevice with a touch sensor. For example, the touch sensor driver 101gives the liquid crystal display driver 102 control signals such asvideo signals and timing signals. For example, the touch sensor driver101 gives the first electrode driver 201 and the second electrode driver202 a control signal for the touch detection control. Then, the touchsensor driver 101 transmits information about a control result of eachfunction (for example, information about the presence or absence oftouching, and a touch position) to the control unit 501.

On the basis of a control signal from the control unit 501 or a controlsignal from the touch sensor driver 101, the liquid crystal displaydriver 102 gives the gate driver 301 and the source driver 302 a signalfor display control at the display area 71 in the panel section 1 of theliquid crystal display device with a touch sensor. A video signal may begiven from the control unit 501 to the liquid crystal display driver102. The gate driver 301 sequentially applies a gate signal (scanningpulse) to a group of the gate lines 41 (gate lines G). Synchronically,the source driver 302 applies a source signal (pixel signal) to a groupof the source lines 42 (source lines S). Accordingly, the pixel signalis applied to each pixel capacitor 43 via the TFT 44 and the holdingcapacitor 45 is charged. Thus, the state of the liquid crystal layer 30is controlled (modulated) for each pixel.

According to the control signal from the touch sensor driver 101, thefirst electrode driver 201 supplies the common voltage Vcom for thecommon electrode COM1 and sequentially applies a signal s 1 serving asthe touch driving signal for the transmitting electrode Tx, to the firstelectrode 51 serving as the transmitting electrode Tx and the commonelectrode COM1 in the panel section 1 of the liquid crystal displaydevice with a touch sensor.

On the basis of the control signal from the touch sensor driver 101, thesecond electrode driver 202 supplies the common voltage Vcom for thecommon electrode COM2, and inputs and detects a signal s2 that is thetouch detection signal for the receiving electrode Rx (sensor patternRx1), with respect to the second electrode 52 serving as the receivingelectrode Rx and the common electrode COM2 in the panel section 1 of theliquid crystal display device with a touch sensor. A signal of adetection result that is the signal s2, which is the touch detectionsignal, detected by the second electrode driver 202 is output to thetouch sensor driver 101. In the second electrode driver 202, the signals2 that is the touch detection signal from the receiving electrode Rx(specifically, the sensor pattern Rx1) is input and integrated, andconverted to a digital signal. On the basis of these process, thepresence or absence of touching in the display area 71 (touch detectionregion) is determined and the coordinates of a touch position iscalculated, so that a signal indicating a result thereof is output. Atouch detection circuit included in the second electrode driver 202includes, for example, an amplifier, a filter, an A/D converter, arectifier smoothing circuit, and a comparator. An input level signalthat is the signal s2 from the receiving electrode Rx is compared withthe threshold voltage Vth by the comparator as described above (FIG. 3),and as a result, a signal indicating the presence or absence of touchingis output.

4-2. Driving Waveforms

FIG. 18 illustrates a timing chart of driving waveforms each for a drivesystem of the panel section 1 of the liquid crystal display device witha touch sensor. The chart corresponds to the driver configuration inFIG. 17 and each driver generates a driving waveform. In the presentdrive system, one horizontal period (1H) is divided into a pixel writingperiod PW in which the liquid crystal display function is activated anda touch sensing period TS in which the touch sensor function isactivated, and the liquid crystal display function and the touch sensorfunction are driven in a time division manner. With respect to theshared electrode sections (the first electrode 51 and the secondelectrode 52), a signal (voltage) corresponding to each function isapplied thereto in a time division manner. As the liquid crystal displaydrive system, for example, a dot inversion drive system or a frameinversion drive system is used.

The drive frequency of each of the pixel writing period PW and the touchsensing period TS may be designed as appropriate. For example, the drivefrequency of the pixel writing period PW is set to 60 Hz, and incontrast, that of the touch sensing period TS is set to twice, that is,120 Hz. That is, in this case, the touch detection is performed twotimes for each one image (pixel) display. The order of the pixel writingperiod PW and the touch sensing period TS in 1 H may be reversed.

An HSYNC signal in FIG. 18( a) defines one horizontal period (1 H). A Gsignal in FIG. 18( b) is applied from the gate driver 301 to the gateline 41 (gate line G). An S signal (image signal) in FIG. 18( c) isapplied from the source driver 302 to the source line 42 (source lineS). The reference Tx (COM1) in FIG. 18( c) indicates a signal appliedfrom the first electrode driver 201 to the first electrode 51. Thereference Rx1 (COM2) in FIG. 18( e) indicates a signal applied from thesecond electrode driver 202 to the sensor pattern Rx1 of the secondelectrode 52. The reference Rx2 (COM2) in FIG. 18( f) indicates a signalapplied from the second electrode driver 202 to the floating pattern Rx2of the second electrode 52. A selection signal Q in FIG. 18( g)indicates a selection signal of the floating pattern Rx2. The selectionsignal Q is generated by the Rx2 selection circuit 222 illustrated inFIG. 19. The selection signal Q is controlled to be turned on in thepixel writing period PW and to be turned off in the touch sensing periodTS.

In the pixel writing period PW, the common voltage Vcom (common drivingsignal) is supplied from the first electrode driver 201 to the firstelectrode 51 (common electrode COM1), and the common voltage Vcom(common driving signal) is supplied from the second electrode driver 202to the second electrode 52 (the receiving electrode Rx (the sensorpattern Rx1 and the floating pattern Rx2)). Accordingly, the firstelectrode 51 (common electrode COM1) and the second electrode 52 (commonelectrode COM2) as a whole are controlled to have common electricpotential (Vcom).

In the touch sensing period TS, the signal s1 as the touch drivingsignal is sequentially applied from the first electrode driver 201 tothe first electrode 51 (receiving electrode Rx), so that the firstelectrode 51 functions as the transmitting electrode Tx and the sensorpattern Rx1 of the second electrode 52 functions as the receivingelectrode Rx. The second electrode driver 202 (specifically, Rx1detection circuit 221 in FIG. 19) detects the signal s2 that is thetouch detection signal from the sensor pattern Rx1.

In the pixel writing period PW, the floating pattern Rx2 is turned onthrough the selection signal Q, and thereby connected to be applied withthe common voltage Vcom. Thus, the floating pattern Rx2 functions as thecommon electrode COM2. In the touch sensing period TS, the floatingpattern Rx2 is turned off through the selection signal Q, and therebydisconnected to be in a floating state. Thus, the floating pattern Rx2does not function as the receiving electrode Rx.

The common driving signal (common voltage Vcom) defines a displayvoltage of each pixel along with a pixel voltage applied to the pixelcapacitor 43, serving as the liquid crystal display function, anddefines the signal s1 as the touch driving signal for the transmittingelectrode Tx (touch drive electrode E1), serving as the touch sensorfunction. FIG. 18 only illustrates a single pulse as a driving waveformin the touch sensing period TS, and an alternating current square wavemay be applied.

4-3. Example of Driver Configuration (1)

FIG. 19 illustrates a configuration example of connection between thedrivers and the electrodes and wiring (wiring pattern of the gate lineG, the source line S, the transmitting electrode Tx, the receivingelectrode Rx, and the like) in the panel section 1 of the liquid crystaldisplay device with a touch sensor corresponding to the configurationsin FIG. 17 and FIG. 18. In the display area 71 of the panel section 1 ofthe liquid crystal display device with a touch sensor, provided are thegate line 41 (gate line G) parallel to the X direction, the firstelectrode 51 serving as the transmitting electrode Tx and the commonelectrode COM1 and also as a stripe-shaped pattern parallel to the Xdirection, the source line 42 (source line S) parallel to the Ydirection orthogonal to the X direction, and the second electrode 52serving as the receiving electrode Rx and the common electrode COM2 andalso as a stripe-shaped pattern parallel to the Y direction. Theseelectrodes and wiring (the gate line G, the source line S, thetransmitting electrode Tx, the receiving electrode Rx, and the like) areconnected to respective drivers as illustrated in the drawings.

In the configuration example of FIG. 19, the second electrode driver 202includes the Rx1 detection circuit 221 and the Rx2 selection circuit222. In the touch sensing period TS, the Rx1 detection circuit 221inputs and processes the signal s2 as the touch detection signal fromeach line of the sensor pattern Rx1, and outputs a resultant Rx signal.The Rx2 selection circuit 222 includes a plurality of switches SW, andeach line of the floating pattern Rx2 is connected to each of theswitches SW. In the configuration example of FIG. 19, a plurality oflines of the floating patterns Rx2 per pixel line are connected to onecommon switch SW. For example, in FIG. 19, four lines of the floatingpattern Rx2 per pixel line are connected to one common switch SW. Oneend of the switch SW is connected to an end of the line of the floatingpattern Rx2, whereas the other end is connected to the common voltageVcom. The selection signal Q of the floating pattern Rx2 is input to acontrol terminal. On the basis of a control of the upper section, aswitching control is performed so that the selection signal Q is turnedon in the pixel writing period PW and the selection signal Q is turnedoff in the touch sensing period TS. Accordingly, the state (function) ofthe floating pattern Rx2 is controlled as described above (FIG. 18).

The Rx2 selection circuit 222 may be arranged outside from the secondelectrode driver 202 separately. For example, the Rx2 selection circuit222 may be mounted on the frame part. The transmitting electrode Tx(touch drive electrode E1) and the receiving electrode Rx (touchdetection electrode E2) may be configured as blocks (an E1 block and anE2 block) commonly connected per a plurality of pixel lines as describedabove (FIG. 4). In this case, an intersecting region of those blocks isthe touch detection unit U.

4-4. Example of Driver Configuration (2)

FIG. 20 is a diagram illustrating a first modification of the example ofthe driver configuration of the liquid crystal touch panel module in thethird embodiment. FIG. 20 illustrates a modification of theconfiguration in FIG. 19. In the configuration of FIG. 20, each of thefloating patterns Rx2 in the panel section 1 of the liquid crystaldisplay device with a touch sensor is independently connected to theswitch SW of an Rx2 selection circuit 222 b, and independently connectedto an Rx detection circuit 221 b. In the second electrode driver 202,each of the switches SW is controlled to be on and off through theselection signal Q of the Rx2 selection circuit 222 b, so that eachfloating pattern Rx2 may be independently turned on and off. Theselection signal Q turns the switches SW on in the pixel writing periodPW, and turns on the switch SW corresponding to a selected floatingpattern Rx2 and off the switches SW corresponding to the others(non-selected floating pattern Rx2) in the touch sensing period TS. Thatis, the second electrode driver 202 can select the line of a desiredfloating pattern Rx2 in the panel section 1 (display area 71) of theliquid crystal display device with a touch sensor to detect an Rxsignal.

5. Advantageous Effects

As described above, according to the embodiments, the panel section 1 ofthe liquid crystal display device with an in-cell capacitive touchsensor has a configuration in which electrode layers are simplified,especially of a sharing type in the vertical electric field mode. Thisenables reducing a step for processing a sensor pattern (receivingelectrode Rx) layer on the front surface of the CF substrate 20 in themanufacturing process, in other words, manufacturing the panel section 1by the simplified manufacturing process. Accordingly, cost reduction andthe like may be achieved while maintaining thinness and highperformance.

Hereinabove, the disclosure devised by the inventor has been describedin detail on the basis of the embodiments. However, the invention is notlimited to the above embodiments and may be variously modified withoutdeparting from the spirits of the disclosure. The embodiments may beused for various electronic apparatuses, such as mobile apparatuses andthe like.

6. APPLICATION EXAMPLE

Next, application examples of the panel section 1 of the liquid crystaldisplay device with a touch sensor described in the embodiments will bedescribed with reference to FIG. 21 to FIG. 28. FIG. 21 to FIG. 28 eachillustrate an example of the electronic apparatus to which the liquidcrystal display device according to the embodiments is applied. Thepanel section 1 of the liquid crystal display device with a touch sensoraccording to the embodiments may be applied to electronic apparatuses inevery field including, but not limited to, a portable terminal devicesuch as a mobile phone and a smartphone, a television apparatus, adigital camera, a portable personal computer, a video camera, a meterprovided on a vehicle, etc. In other words, the panel section 1 of theliquid crystal display device with a touch sensor according to theembodiments may be applied to electronic apparatuses in every field thatdisplay a video signal input from the outside or a video signalgenerated in the inside as an image or a video. The electronicapparatuses includes a control device that supplies a video signal tothe panel section 1 of the liquid crystal display device with a touchsensor and controls the operation of the panel section 1 of the liquidcrystal display device with a touch sensor. The embodiments may be usedfor various electronic apparatuses such as on-vehicle equipment and thelike. For example, the panel section 1 of the liquid crystal displaydevice with a touch sensor may be part of a meter unit which is attachedto an on-vehicle exterior panel to serve as a fuel meter, a watertemperature meter, a speedometer, a tachometer, and the like.

6-1. Application Example 1

An electronic apparatus illustrated in FIG. 21 is a television apparatusto which the panel section 1 of the liquid crystal display device with atouch sensor according to the embodiments is applied. For example, thetelevision apparatus has a video display screen unit 510 including afront panel 511 and a filter glass 512, and the video display screenunit 510 is the panel section 1 of the liquid crystal display devicewith a touch sensor according to the embodiments.

6-2. Application Example 2

An electronic apparatus illustrated in FIG. 22 and FIG. 23 is a digitalcamera to which the panel section 1 of the liquid crystal display devicewith a touch sensor according to the embodiments is applied. Forexample, this digital camera includes a light-emitting unit 521 forflash, a display unit 522, a menu switch 523, and a shutter button 524.The display unit 522 is the panel section 1 of the liquid crystaldisplay device with a touch sensor according to the embodiments. Asillustrated in FIG. 22, this digital camera has a lens cover 525, and ataking lens is exposed by sliding the lens cover 525. The digital cameracan take a digital photo by imaging incident light through the takinglens.

6-3. Application Example 3

An electronic apparatus illustrated in FIG. 24 represents an externalappearance of a video camera to which the panel section 1 of the liquidcrystal display device with a touch sensor according to the embodimentsis applied. For example, this video camera includes a body part 531, alens 532 for photographing a subject provided on a front side surface ofthe body part 531, a start/stop switch 533 used at the time ofphotographing, and a display part 534. The display unit 534 is the panelsection 1 of the liquid crystal display device with a touch sensoraccording to the embodiments.

6-4. Application Example 4

An electronic apparatus illustrated in FIG. 25 is a portable personalcomputer to which the panel section 1 of the liquid crystal displaydevice with a touch sensor according to the embodiments is applied. Forexample, the laptop personal computer has a body 541, a keyboard 542 forinputting characters and the like, and a display unit 543 for displayingan image. The display unit 543 is configured by the panel section 1 ofthe liquid crystal display device with a touch sensor according to theembodiments.

6-5. Application Example 5

An electronic apparatus illustrated in FIG. 26 and FIG. 27 is a mobilephone to which the panel section 1 of the liquid crystal display devicewith a touch sensor is applied. FIG. 26 is a front view of the mobilephone in an open state. FIG. 27 is a front view of the mobile phone in afolded state. For example, the mobile phone is configured by connectingan upper housing 551 and a lower housing 552 via a connection part(hinge part) 553, and includes a display 554, a sub-display 555, apicture light 556, and a camera 557. The panel section 1 of the liquidcrystal display device with a touch sensor is attached to the display554. Accordingly, the display 554 of the mobile phone may have afunction for detecting a touch operation in addition to a function fordisplaying an image.

6-6. Application Example 6

An electronic apparatus illustrated in FIG. 28 is a mobile informationdevice operating as a portable computer, a multi-functional mobilephone, a portable computer that can perform voice call, or acommunicatable portable computer. The device may be called a smartphoneor a tablet device. This mobile information device has a display unit562 on a surface of a housing 561, for example. The display unit 562 isthe panel section 1 of the liquid crystal display device with a touchsensor according to the embodiments.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A liquid crystal display device with a touch sensor having a liquid crystal display function and a touch sensor function, the liquid crystal device comprising: a first substrate including a pixel electrode and a first electrode; a second substrate including a second electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein upon the liquid crystal display function being activated, the pixel electrode is supplied with a pixel signal, and the first and second electrodes are supplied with common voltage, and upon the touch sensor function being activated, the first electrode is applied with a first signal and the second electrode is configured to receive the first signal to be a second signal as a touch detecting signal; the first electrode includes patterns of electrodes along a first direction, each of the patterns being configured to form a holding capacitor, the second electrode includes patterns of electrodes along a second direction on the second substrate, the patterns of the first electrode on the first substrate face the patterns of second electrode on the second substrate, and the patterns of first electrode cross the patterns of second electrode in a planar view.
 2. The liquid crystal display device with a touch sensor according to claim 1, wherein the patterns of the second electrode includes a first pattern configured to be used as a sensor pattern through which the second signal is detected upon the touch sensor function being activated and a second pattern configured to be separated from the outside upon the touch sensor function being activated, and the first pattern and the second pattern have therebetween a slit to generate a fringe electric field.
 3. The liquid crystal display device with a touch sensor according to claim 2, wherein the first substrate includes a source line that is connected to the pixel electrode, and the first pattern is arranged to overlap the source line in a planar view.
 4. The liquid crystal display device with a touch sensor according to claim 2, further comprising a selection circuit including a switch configured to switch a connection state between the second pattern and the selection circuit to ON or OFF, wherein the second pattern is supplied with the common voltage when the connection state is turned ON.
 5. The liquid crystal display device with a touch sensor according to claim 2, wherein the first pattern has a portion overlapping the second pattern in a plane view, a width of the portion being smaller than that of the other portion.
 6. The liquid crystal display device with a touch sensor according to claim 1, further comprising a first electrode driver connected to the first electrode; and a second electrode driver connected to the second electrode, wherein the first electrode driver is configured to supply the common voltage to the first electrode in a pixel writing period of a horizontal period and apply the first signal to the first electrode in a touch sensing period of the horizontal period, and the second electrode driver is configured to supply the common voltage to the second electrode in the pixel writing period of the horizontal period and detect the second signal through the second electrode in the touch sensing period of the horizontal period.
 7. The liquid crystal display device with a touch sensor according to claim 2, further comprising a first electrode driver connected to the first electrode; and a second electrode driver including a detection circuit connected to the first pattern of the second electrode; and a selection circuit connected to the second pattern of the second electrode, wherein the detection circuit is configured to calculate presence or absence of touching and/or a position of the touching based on the second signal from of the first pattern and output a resultant signal, and the selection circuit includes a switch connected to the second pattern and is configured to turn on the switch to supply the common voltage to the first electrode in a pixel writing period of a horizontal period and turn off the switch in a touch sensing period of the horizontal period.
 8. The liquid crystal display device with a touch sensor according to claim 6, further comprising: a gate line on the first substrate; a source line on the first substrate; a color filter on the second substrate; a gate driver connected to the gate line; a source driver connected to the source line; a first controller that is connected to the first electrode driver and the second electrode driver and that is configured to perform driving control of the touch sensor function; and a second controller that is connected to the gate driver and the source driver and is configured to perform driving control of the liquid crystal display function.
 9. An electronic apparatus including a liquid crystal display device with a touch sensor having a liquid crystal display function and a touch sensor function, the liquid crystal device comprising: a first substrate including a pixel electrode and a first electrode; a second substrate including a second electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein upon the liquid crystal display function being activated, the pixel electrode is supplied with a pixel signal, and the first and second electrodes are supplied with common voltage, and upon the touch sensor function being activated, the first electrode is applied with a first signal and the second electrode is configured to receive the first signal to be a second signal as a touch detecting signal; the first electrode includes patterns of electrodes along a first direction, each of the patterns being configured to form a holding capacitor, the second electrode includes patterns of electrodes along a second direction on the second substrate, the patterns of the first electrode on the first substrate face the patterns of second electrode on the second substrate, and the patterns of first electrode cross the patterns of second electrode in a planar view. 